We report for the first time, the influence of two plasticizers namely, glycerol and xylitol and the effect of relative humidity (RH), measured as equilibrium water activity, on the glass-rubber transition temperature (T_g) of low amylose (LA) starch polymer – from maize starch. Strong antiplasticization behaviour is shown by both plasticizers at their lower concentrations region at very low RH values up to 22% and xylitol continued to show antiplasticization tendencies upto RH value of 40%. It was found that glycerol is a better plasticiser than xylitol at low values of RH; and even for high plasticizer concentration, viz., 20%, the glycerol samples had a 20C lower T_g value as compared to xylitol samples. If T_g is to be understood from a free volume concept, this is an interesting finding because it highlights that the affinity of low amylose starch to water increases the matrix free volume at a threshold RH value (around 63%) and is not affected by addition of either plasticizer for up to 20 wt%. This is further supported by T_g data at very high RH values up to 95% with no significant change in sample T_g for either plasticizer.